1. Field of the Invention
The present invention relates to compositions, devices, kits and methods for the detection of roundworm in mammals. More particularly, the present invention relates to polypeptides and polypeptide compositions, antibodies and antibody compositions, devices, kits, and methods for detecting the presence or absence of roundworm antigen in a sample from a mammal that may also include one or more of hookworm, whipworm, and heartworm antigen.
2. Description of the Prior Art
Adult roundworms live in the small intestine and lay eggs that pass out in the feces. In the environment, infective larvae remain within the eggs and develop into an infective stage after approximately three weeks at optimal temperatures. The infective eggs enter a host by ingestion and hatch in the small intestine. In dogs less than five weeks of age, larvae migrate through the tissue and into the bloodstream before eventually reaching the lung and trachea where additional development occurs. The host coughs up and swallows the larvae, which molt into adults that reside in small intestine. Larvae that hatch within dogs greater than five weeks of age or within other animals, including humans, are capable of traveling to a wide range of tissues including the liver, lungs, heart, brain, and skeletal muscle. These larvae subsequently arrest their development and encyst in the tissue of the host. In pregnant and lactating dogs, encysted larvae can become reactivated and cause intestinal infection in the mother, migrate to the uterus and directly infect the fetus through the placenta, or migrate to the mammary tissue and infect nursing animals. Parasitic roundworms cause disease not only in their animal hosts, but are also the etiological agents of larval migrans syndrome as well as severe enteritis and allergic reactions in humans, which occurs after ingestion of infectious eggs from the environment or ingestion of larvae found within liver, meat or other tissues of paratenic hosts.
Intestinal roundworm infection is common in animals and, if left untreated, can cause serious disease and even death. Although it is relatively easy to diagnose a roundworm-infected animal as having a parasitic worm (helminth) infection of some type, it is significantly more difficult to identify roundworm, specifically, as the causative worm. This is a problem because roundworm infections are best treated when the infected animal's caregiver has knowledge that roundworm is the specific source of the infection. In addition, humans who may come in contact with the infested animal or its excretions may be advised to take precautions against acquiring the parasite. In this context, it is important to determine the worm species with high specificity, as some helminths, such as roundworms and hookworms, can cause significant disease (e.g., larva migrans) in humans, while it is generally accepted that whipworm does not play a zoonotic role of importance in humans.
Current methods for diagnosis of roundworm infections primarily involve microscopic examination of fecal samples, either directly in fecal smears or following concentration of ova by flotation in density media. Despite this procedure's high adoption, the method has significant shortcomings. These microscopic methods are time consuming, are unpleasant, require specialized equipment and can have low specificity and sensitivity [Dryden et al., 2005, Vet Therap. 6(1), 15-28]. In addition, the accuracy of results of these methods is highly dependent upon the skill and expertise of the operator.
Stool handling is disagreeable and hazardous. Sanitary and inoffensive procedures for processing stool are awkward and often complex. Such procedures may include weighing, centrifuging and storing, and are difficult except in a clinical laboratory equipped with a suitable apparatus, protective equipment, and a skilled technician. Therefore, any reduction in the number of steps required to perform a fecal test and any reduction in contact between test operator and the test material is desirable. Clinical laboratories have been using the immunoassay methods for the detection of various viruses, bacteria and non-helminth parasites and organisms in feces. However, there remains a need for a simple immunoassay method for the detection of a parasitic worm infection, and roundworm infection in particular in feces, whole blood or in serum.